James h



(No Model.)

J. H. MINER.

SAW LEVEL.

Patented Jupe 3, 1890.

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UNITE STATES PATENT OFFICE.

JAMES H. MINER, OF BATON ROUGE, LOUISIANA, ASSIGNOR TO THE E. O. ATKINS& COMPANY, OF INDIANAPOLIS, INDIANA.

SAW- LEVEL.

SPECIFICATION forming part of Letters Patent No. 429,144,'dated June 3,1890.

7 Application filed November 19, 1889. Serial No. 330,866. (N 0 model.)

To all whom it may concern.-

Be it known that 1, JAMES H. MINER,aciti zen of the United States,residing at Baton Rouge, in the parish of East Baton Rouge and State ofLousiana, have invented certain new and useful Improvements inSaw-Levels, of which the following is a specification.

The object of my said invention is to provide a level for use indetermining the tension of circular saws, which shallbe cheap inconstruction, convenient in operation, and by which the desired resultcan be accurately and easily ascertained, as will be hereinafter morefully described and claimed.

Referring to the accompanying drawings, which are made a part hereof,and on which similar letters of reference indicate similar parts, Figure1 is a view in elevation of a saw-level embodying my said invention,being shown in position for use on a saw-plate, which is shown insection; Fig. 2, a sectional view on the dotted line 2 2 in Fig. 1; Fig.3, a

view similar to Fig. 1, illustrating a modification in construction;Fig. 4, a sectional view on the dotted line 4 4. in Fig. 3; Fig. 5, aview showing another modification in construction; Fig. 6, a sectionalview on the dotted line 6 6 in said figure; Fig. 7, a detail view, on anenlarged scale, illustrating yet another modification in construction;and Fig. 8, a sectional view on the dotted line 8 S in Fig. 7.

In said drawings the portions marked A represent the saw-plate, and Bthe level.

As is well known, circular saws are commonly made of a slightly-dishedformation, as illustrated in the drawings in a somewhat exaggerateddegree. The plate, being straight from the eye to the edge, is termedtight or firm with reference to its radii; but if a straight-edge isplaced upon the saw, as indicated in the drawings, it will fall awaytherefrom at the center, and it is therefore termed loose with referenceto its whole diameter. The degree of looseness is termed the tension ofthe saw, and is governed by the size or style of the saw, the speed atwhich it is to run, and the work it is designed to do. The saw Atherefore represents any circular saw the tension of which it is desiredto ascertrain The level B is a bar of wood or metal or wood and metal,as may be preferred, the edge of which is formed perfectly straight andthe back of which is of the form to give it necessary strength,preferably substantially of the form shown in the drawings.

In the construction shown in Fig. 1 an indicator B, formed with an angleor two arms, is pivoted at the point of the angle in a sliding bearingmounted and adjustable to various positions in a longitudinabslot 6,formed in the level parallel with its front edge. One arm of saidindicator is arranged to point downward and measure the tension and theother extends longitudinally, and a vertical scale or scales 1) arearranged on the face of the level, over which this point of theindicator is adapted to move and point out thereon the degree of tensionwhich the other point measures. A scale is also provided along one edgeof the slot in which the sliding bearing is mounted, by which theposition to which it is desired to adjust the indicator may bedetermined.

The means shown for securing this device in the position desiredconsists simply of a thumb-nut on the opposite end of the pivotbolt, asshown in Fig. 2, which is adapted to bear against the opposite face ofthe level or a washer thereomwhereby the parts may be tightenedsufficiently to render them rigid in position.

In Fig. 3, instead of a slot, I have shown a series of holes arranged ona line parallel with the front edge of the level, into each of which thepivot-bolt is adapted to be placed, or in which separate indicators maybe mounted. In both forms the longitudinal arm or indicator-point ispreferably of considerably greater length than the vertical ormeasuring-point, and thus its point moves a much greater distance thandoes the point of the vertical point, and thus a very slight tensionwill be indicated by a movement sufficient to be easily and accuratelydiscerned. In operation the level is laid upon the saw the tension ofwhich it is desired to ascertain, and the pivot on which the indicatoris mounted is adjusted that distance from the end of the level whichwill correspond with the point upon the saw at which it is desired toknow its tension. The longitudinal arm is then raised up until the pointof the vertical arm strikes the surface of the saw, when by reference tothe figures on the scale opposite the point of the longitudinal arm thetension of the point where the saw is tested is seen. It being desiredto test the saw at another point, the indicator is moved to such pointas desired and the operation repeated. A register being kept of thenumber of the saw and of its tension at various points, an exactduplicate of said saw can be readily produced at any time, as will bereadily understood.

In Fig. 5 I have shown a series of vertical slots having adjustableindicator fingers therein with Vertical scales arranged oppositethereto, which construction can be used in lieu of the one abovedescribed and the same result obtained; but I prefer the constructionshown in Figs. 1 and 8, because of the greater accuracy which can besecured by reason of the greater movement of the point which registerswith the scale in relation to the point which measures the tension,which thus enables a very small or slight tension to be indicated by amark easily discernible.

It will be understood, of course, that an indicator may be fixedlypivoted on each side of the level in different positions, and a levelthus provided which will answer for ordinary purposes without beingadapted for any adjustment at all.

In Figs. 7 and 8 I have illustrated another form of indicator which maybe substituted for the indicator shown in Figs. 1 and 3. It consists ofa plate O, having a stud c on its rear side, adapted to be inserted inthe bearing provided for the pivot on which the indicator shown in theother figures is pivoted, being secured in position by means of athumbnut 0. I11 its front side it is provided with a vertical dovetailedgroove in which is mounted a sliding indicator 0, provided with anindicator-point c and a scale on the side of the plate opposite saidpoint for indicating the tension. These modifications and many othersmay of course be substituted for the form shown in the principal figuresof the drawings; but I prefer said'form because of the greater accuracywith which the tension may be ascertained by means of the relativelengths of the points which indicate and measure the tension, as beforedescribed.

Having thus fully described my said invention, what I claim as new, anddesire to secure by Letters Patent, is

1. A saw-level consisting of a straightedge provided. with .a movableindicator thereon and a scale arranged thereon with said indicator fordetermining the tension of the saw, substantially as set forth.

2. A saw-level consisting of a straight-edged bar having an indicatorthereon formed of two arms extending at any angle from each other, oneof which is arranged to extend below said bar to measure the tension ofthe saw, said indicator being pivoted on said bar, and a scale beingprovided opposite the point of the other arm by which the tension thusmeasured may be ascertained, substantially as set forth.

3. Asaw-level consisting of a straight-edged I bar formed with alongitudinal slot therein parallel with said straight-edge, anadjustable bearing mounted in said slot, and an indicatorarm pivoted insaid bearing and formed with two arms extending out from said pivot atan angle with each other, a scale being formed on said bar opposite thepoint of one arm, substantially as set forth.

In witness whereof I have hereunto set my hand and seal, at Baton Rouge,Louisiana, this 12th day of November, A. D. 1889.

JAMES H. MINER. 1,. s.]

Witnesses:

M. P. ROBERTSON, F. H. WooDs.

